Antigorite
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Description
A variety of Serpentine named after the community of Antigorio in Italy. Antigorite was was first described and named for a specimen from the Antigorio valley in the Novara province of Italy. It is commonly used as a gemstone in jewelry and carvings.
Synonyms and Related Terms
serpentine; antigorita (Esp.); antigorite (Port.); Antigorit (Deut.); antigoriet (Ned.)
Physical and Chemical Properties
- Monoclinic, crystals rare, usually massive
- Cleavage = perfect
- Fracture = conchoidal
- Luster = vitreous, greasy
- Streak = greenish-white
- Low birefringence
- May be translucent to opaque
- Translucent stones may show black inclusions, white veining, or moss-like shapes
| Composition | (Mg,Fe2+)3Si2O5(OH)4 |
|---|---|
| Mohs Hardness | 3.5 - 4.0 |
| Density | 2.5-2.6 g/ml |
| Refractive index | 1.56-1.57 |
| Birefringence | 0.005 - 0.006 |
Resources and Citations
- Mindat.org: antigorite
- Gem Identification Lab Manual, Gemological Institute of America, 2016.
- Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 702
- B.Ford et al, Studies in Conservation, vol 39, pp. 57-69. for formula
- Wikipedia: Antigorite [Accessed Aug. 30 2005 and Dec 2022]